Indocyanine Green Fluorescence Imaging, Sentinel Lymph Node Mapping in Patients With Vulvar Cancer: Peritumoral Injection Dosage and Waiting Times in Our Experience

According to The European Society of Gynaecological Oncology (ESGO) guidelines, the investigators decided to treat patients with vulvar squamous cell carcinoma (vSCC), FIGO stage IB with radical vulvectomy, sentinel lymph node search, and removal with indocyanine green (ICG) subsequent bilateral inguinofemoral lymphadenectomy.

Intraoperative imaging system The SPY Portable Handheld Imager (SPY-PHI) © Stryker was used as the intraoperative imaging device. This device uses SPY fluorescence imaging technology to visually assess blood circulation in blood vessels and associated tissue perfusion during surgery. The design of SPY-PHI makes the device versatile, enabling the operator to frame the operating field and use the acquired images in real-time, integrating fluorescence signal data with white light images in real-time. The SPY Portable Handheld Imaging System Camera, with integrated optics and cables for real-time fluorescence imaging in visible light and near-infrared, is ideal for open surgery.

Intraoperative detection of the sentinel lymph node The fluorescent agent was administered to patients placed in the lithotomy position under general anesthesia. Indocyanine green (ICG) prepared with a 25 mg vial of green indocyanine green (ICG) (Pulsion Medical Systems AG, Munich, Germany) diluted in 50 mL of water for injections (B. Braun Medical) was used, resulting in a concentration of 0.5 mg/mL. Injection of 1 ml per quadrant was administered in the three quadrants around the vulvar lesion. After the injection, the infrared camera, equipped with a movable arm, was placed in front of the patient to detect transcutaneous fluorescence during surgery. Subsequently, the SLN was localized based on the fluorescence intensity. The intraoperative fluorescence detection camera system was used to open, identify, and remove the SLN and the vulvectomy of the groin. After the excision, the capture of the residual lymphatic pathway could be seen bilaterally through the infrared camera. Additionally, all SLNs were subject to ex vivo imaging due to the presence of fluorescence. The excised SLNs were sent to pathological anatomy and processed according to the standard SLN protocol.